Shoe wear-out sensor, body-bar sensing system, unitless activity assessment and associated methods

ABSTRACT

A shoe wear out sensor ( 100,210,310 ) includes at least one detector ( 104,312 ) for sensing a physical metric that changes as a sole of a shoe wears out, a processor ( 102 ) configured to process the physical metric over time to determine if the shoe is worn out, and an alarm ( 106 ) for informing a user of the shoe when the sole is worn out. A body bar sensing system ( 500 ) includes a housing ( 502 ) with at least one detector ( 506 ) for sensing a physical metric that indicates a repetition movement of the housing when attached to the body bar, a processor ( 504 ) for processing the physical metric over time to determine repetitions thereof, and a display ( 508,512 ) for informing a user of the repetitions. A system assesses activity and displays a unitless activity value. A detector senses activity of a user. A processor reads sensed activity data from the detector. A display displays the unitless activity value. An enclosure houses the detector and the processor. The processor periodically reads the sensed activity data from the detector and processes the data to generate an activity number, the number being used to generate the unitless activity value based upon a maximum number and a display range.

RELATED APPLICATIONS

This application claims priority under 35 USC §371 to PCT application No. PCT/US2006/040970, filed Oct. 18, 2006, which claims the benefit of U.S. Provisional Application No. 06/728,031. These applications are hereby incorporated herein by reference in their entireties.

BACKGROUND

Shoes (including sneakers or boots, for example) provide comfort and protection for feet. More importantly, shoes provide physical support for feet to reduce risk of foot injuries. A shoe is often necessary to provide support during intense physical activity, such as running, soccer and American football. As a shoe wears, physical support provided by the shoe decreases, thereby reducing associated protection from injury. When a critical wear level is reached, even if the shoe looks like it is not particularly worn, the shoe may not provide adequate support and may, in fact, cause damage to feet.

SUMMARY

In one embodiment, a shoe wear out sensor includes at least one detector for sensing a physical metric that changes as a shoe wears out, a processor configured to process the physical metric, over time, to determine if the shoe is worn out, and an alarm for informing a user of the shoe when the sole is worn out.

In another embodiment, a system determines the end of a shoe's life. Use of the shoe is sensed by at least one detector. A processor is configured to measure the use of the shoe and to determine if the shoe is worn out. An alarm informs a user of the shoe when the shoe is worn out.

In another embodiment, a body bar sensing system includes a housing with at least one detector for sensing a physical metric that indicates repeated movement of the housing when attached to the body bar, a processor configured to process the physical metric, over time, to determine repetitions thereof, and a display for informing a user of the repetitions.

In another embodiment, a system assesses activity and displaying a unitless activity value and includes a detector for sensing activity of a user of the system, a processor for processing sensed activity data from the detector, a display for displaying the unitless activity value, and an enclosure for housing the detector and the processor. The processor periodically reads the sensed activity data from the detector and processes the data to generate an activity number, the number being used to generate the unitless activity value based upon a maximum number and a display range.

In another embodiment, a method determines a unitless activity value for a desired period of activity. A period accumulator is cleared prior to the start of the activity period A detector is periodically sampled to obtain data that is processed to determine a number representative of the sampling period. The number is added to the period accumulator. The unitless activity value is then determined based upon the period accumulator, a maximum activity number and a display range. The unitless activity value is then displayed. The sampling, processing and adding are repeated until data is sampled for the desired period of activity.

In another embodiment, a method assesses activity unitlessly by detecting motion of a user, processing the detected motion, over time, to determine an activity value, ratioing the activity value to a maximum activity value, and reporting a scaled unitless activity value to the user based upon the ratio and a scale.

A software product has instructions, stored on computer-readable media, that, when executed by a computer, perform steps for determining a unitless activity value for a desired period of activity, including instructions for: detecting motion of a user, processing detected motion, over time, to determine an activity value, ratioing the activity value to a maximum activity value, and reporting a scaled unitless activity value to the user based upon the ratio and a scale.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows one exemplary embodiment of a shoe wear-out sensor.

FIG. 2 shows one exemplary embodiment of a shoe with a shoe wear out sensor.

FIG. 3 shows another exemplary embodiment of a shoe with a shoe wear out sensor.

FIG. 4A shows one exemplary process for determining shoe wear out.

FIG. 4B shown one exemplary process for determining shoe wear out.

FIG. 4C shows one exemplary process for determining shoe wear out.

FIG. 4D shown one exemplary process for determining shoe wear out.

FIG. 5 shows one body bar sensing system embodiment.

FIG. 6 shows one part of an exemplary body bar with a body bar sensing system embodiment attached.

FIG. 7 shows one part of a body bar in an embodiment showing a weight and a body bar sensing system that secures the weight onto the body bar.

FIG. 8 shows one exemplary process for reporting body bar usage.

FIG. 9 shows an embodiment of a sensor that unitlessly assesses activity.

FIG. 10 shows a process for unitlessly determining activity.

DETAILED DESCRIPTION OF THE FIGURES

FIG. 1 shows one shoe-wear out sensor 100. Sensor 100 includes a processor 102, a detector 104 and an alarm 106. A battery 108 may be used to power processor 102, detector 104 and alarm 106; alternatively, a magnetic coil generator (not shown) or other mechanical motion-to-electricity conversion device may be employed with sensor 100 to power these elements. Detector 104 is for example an accelerometer and/or a force sensing resistor (FSR). Alarm 106 is for example a light emitting diode (LED) and/or a small speaker and/or a small sound actuator (e.g., a buzzer, piezoelectric beeper etc).

FIG. 2 shows a shoe 200 with a shoe-wear out sensor 210. Shoe 200 is for example a running or sport shoe, boot (e.g., a snowboard or hiking boot), slipper, dress shoe or flip-flop; shoe 200 may alternatively be an orthopedic shoe for providing special foot support. Sensor 210 may represent sensor 100, FIG. 1. In the illustrated embodiment, shoe 200 has a sole 202 and an upper part 204. Sole 202 has an outsole 206 and a heel 208. Sensor 210 is shown contained within heel 208; however sensor 210 may be placed elsewhere within or on the shoe to function similarly.

FIG. 3 shows one exemplary embodiment of a shoe with a shoe-wear out sensor 310. Sensor 310 may again represent sensor 100, FIG. 1. Shoe 300 is shown with a sole 302 and an upper part 304. Sole 302 has an outsole 306 and a heel 308. Shoe 300 may again represent, for example, a running shoe, sports shoe or orthopedic shoe (or other type of shoe or boot). Electronics 310 a of sensor 310 are shown contained within heel 308; but detector 312 is shown located within outer sole 306, illustrating that the elements of sensor 100 (FIG. 1) may be dispersed to various locations of the shoe while providing similar functionality. Detector 312 is for example detector 104, FIG. 1; it may thereby be a force sensing resistor and/or a piezoelectric foil that is electrically connected, via connection 314, to electronics 310 of sensor 310. If detector 312 is a piezoelectric foil (or other piezoelectric device), use of shoe 300 results in flexing of detector 312 which may generate sufficient electricity to power electronics of sensor 310, avoiding the need for battery 108.

FIGS. 1, 2 and 3 are best viewed together with the following description. Sensor 100 may be embedded in a shoe (e.g., sensors 210, 310 within shoes 200, 300) and configured to determine when that shoe has “worn out”. It then informs the user, via alarm 106, that it is time to buy a new shoe (usually a new pair of shoes). In an embodiment, alarm 106 is an LED 217 that is positioned at the outside of the shoe such that it may be seen, when activated, by the user of the shoe, as illustratively shown in FIG. 2.

Processor 102 may operate under control of algorithmic software 103 (which is illustratively shown within processor 102, though it may reside elsewhere within sensor 100, for example as stand alone memory of sensor 100). Algorithmic software 103 for example includes algorithms for processing data from detector 104 to determine when a shoe is worn out.

FIG. 4A for example illustrates one process 400 performed by processor 102 of FIG. 1. In step 402, processor 102 samples detector 104 to determine a physical metric associated with the shoe. In an example of step 402, detector 104 is an accelerometer and thereby provides acceleration data resulting from movement of the shoe upon a surface as the physical metric. For example, as the shoe strikes the ground when in use, processor 102 takes a plurality of samples using detector 104 to form an impact profile. In step 404, processor 102 processes the physical metric and compares it against a predetermined threshold, response curve or other data reference. In an example of step 404, processor 102 compares the impact profile determined from the accelerometer against an impact profile of a “new” shoe. In another example of steps 402, 404, the physical metric is power spectral density corresponding to certain frequencies of interest; and the power spectral density is compared, during use of the shoe, to a data reference containing power spectral density of a new or acceptably performing shoe. If the current data (i.e., physical metric) is too large or exceeds the data reference, for example, then processor 102 sets off alarm 106 (e.g., lights LED 217) in step 406. In one embodiment, upon first use of the shoe, processor 102 determines an impact profile of the new shoe that is then used (e.g., as the threshold or data reference) in comparison against subsequently determined impact profiles. Or, upon first use of the shoe, for example, processor 102 may store the appropriate data reference (e.g., power spectral density or threshold) for comparison against data captured in latter uses of the shoe. In this way, therefore, process 400 may be efficiently used to inform a user of shoe wear out.

As noted, data from detector 104 may be processed in the frequency domain (e.g., using Fourier transforms of data from detector 104) so as to evaluate, for example, power spectral density of the physical metric (e.g., acceleration or force), in step 404. In this manner, therefore, a range of frequencies may be evaluated (e.g., an area under the curve for certain frequencies may be integrated) from detector 104 and then compared to similar data (as the threshold) of a new shoe. As a shoe wears, the elasticity of the material from which it is made changes; thus the ability of the material to absorb the shock of the shoe contacting the ground deteriorates, resulting in more shock force being transferred to the foot within the shoe. By determining the increase of the shock force above the threshold, in this embodiment, the wear on the shoe may be determined.

We now specifically incorporate by reference the teachings and disclosure of: U.S. Pat. No. 6,539,336; U.S. Pat. No. 6,266,623; U.S. Pat. No. 6,885,971; U.S. Pat. No. 6,856,934; U.S. Pat. No. 6,8963,818; U.S. Pat. No. 6,499,000; and U.S. application Ser. No. 10/297,270. These patents and applications provide useful background, power sensing and weight/movement monitoring techniques suitable for use with the teachings of this present application.

In an embodiment, similar to the embodiment of FIG. 3, processor 102 determines wear of shoe 300 based upon weight of the user of shoe 300. By using signals from detector 312 to determine an approximate weight of the user of shoe 300 (for example by using a pressure sensor and fluid-filled cavity as detector 104), processor 102 may determine a life expectancy of shoe 300. Since the wear on the shoe is roughly proportional to the weight applied by the wearer, during activity, by determining the weight of the wearer and the amount the shoe is used (e.g., how often and how long the shoe is used), processor 102 may thus determine shoe wear with increased accuracy. That is, a shoe used by someone who spends most of their time sitting at a desk receives less wear that a shoe used by someone who spends most of the day standing on their feet.

In another embodiment, by sensing when the shoe is used—or for how long—the teachings herein may instead be applied so as to set off the alarm after a term or time of use has expired. For example, if a shoe is specified for use to at least 100 hours or 500 miles (or other similar metric specified by the shoe manufacturer), then by sensing weight or acceleration (or other physical metric, via detector 104) that use may be determined; processor 102 then activates alarm 106 when the use is exceeded. For example, using one or more accelerometers as detector 104, speed of the shoe may be determined through operation of processor 102 using an appropriate algorithm within software 103; this processor 102 then uses the speed information to determine distance traveled and sets off alarm 106 when, for example, the manufacturer's specified distance use is met. Illustratively, in another example, if the manufacturer specifies that the shoe may be used under normal conditions for 500 hours (or some other time), then detector 104 in the form of an accelerometer may determine when the shoe is in use; processor 106 then determines the period of use, over time (e.g., weeks and months) and sets off alarm 106 when the accumulated use exceeds the specified limit.

FIG. 4B for example illustrates one process 450 performed by processor 102 of FIG. 1 for determining shoe wear out. In step 452, processor 102 samples detector 104 to determine one or more physical metrics associated with the shoe. In an example of step 402, detector 104 includes a fluid filled cavity and a pressure sensor and thereby provides a signal representative of force upon the shoe (e.g., a value representative of the weight of the user of the shoe). For example, as the shoe is used, processor 102 takes a plurality of pressure reading from detector 104. In step 454, processor 102 determines an approximate weight upon the shoe based upon samples of step 452. In one example of step 454, processor 102 utilizes algorithms of software 103 to determine an approximate weight of the user of the shoe based upon pressure values sensed by detector 104. In step 456, process 102 determines the duration of the shoe's use. In one example of step 456, processor 102 utilizes algorithms of software 103 to measure the duration that the shoe is used based upon readings from detector 104 and an internal timer of processor 102. In step 458, processor 102 determines the shoe use for the sample period of step 452. In one example of step 458, processor utilizes algorithms of software 103 to determine a use factor based upon the determined weight of step 454 and the duration of use of stop 458. In step 460, processor 102 determines remaining life of the shoe based upon the determined shoe use of step 458. In one example of step 460, processor 102 maintains a cumulative value of usage determined in step 458 for comparison against a manufacturer's expected usage of the shoe. In step 462, processor 102 enables alarm 106 if the shoe's life is exceeded. Steps 452 through 462 repeat periodically throughout the life of the shoe to monitor shoe usage based upon wear determined from the weight of the user and the duration of use.

In the above description of process 450, it is not necessary that weight be determined. Rather, in an embodiment, it may instead be determined that the shoe is in “use” based on an algorithm using the pressure or force based detector 104; and then this use is accumulated time-wise to determine when the shoe's life expectancy is exceeded. For example, once a user puts weight onto this detector (in this embodiment), then processor 102 detects (through use of an algorithm as software 103) that the shoe is in use due to the presence of weight onto detector 104.

FIG. 4C for example illustrates one process 470 performed by processor 102 of FIG. 1 for determining shoe wear out. In step 471, processor 102 samples detector 104 periodically over a defined period. In one example of step 471, detector 104 is an accelerometer that is sampled periodically by processor 102 over a period of ten seconds. In step 472, processor 102 determines if the shoe is in use. In one example of step 472, processor 102 utilizes algorithms of software 103 to process the samples of step 471 to determine if the shoe is in use. Step 473 is a decision. If, in step 473, processor 102 determines that the shoe is in use, process 470 continues with step 474; otherwise process 470 continues with step 475. In step 474, processor 102 adds a value representative of the defined period of step 471 to an accumulator. In one example of step 474, a non-volatile accumulator is incremented by one, where the one represents a period of ten seconds. Step 475 is a decision. If, in step 475, processor 102 determines that the shoe is worn out, process 470 continues with step 476; otherwise process 470 continues with step 471. In one example of the decision of step 475, processor 102 compares the use accumulator of step 474 against a value representative of the expected life of the shoe. Steps 471 through 475 repeat throughout the lifetime of the shoe. As appreciated, power saving measures may be used within sensor 100 when it is determined that the shoe in which sensor 100 is installed is not in use. In step 476, processor 102 enables alarm 106. In one example of step 476, processor 102 may periodically activate LED 217, FIG. 2, until battery 108 is exhausted.

Process 470 thus determines the wear on a shoe by measuring the amount of use and comparing it against the expected use defined by a manufacturer, for example. In an embodiment, the use accumulator of step 474 is a timer within processor 102. This timer is started when step 473 determines that the shoe is in use and is stopped when step 473 determines that the shoe is not in use. This timer thus accumulates, in real time, the use of the shoe for comparison against a manufacturer's expected use. In another embodiment, step 472 may determine the number of steps a shoe has taken such that the use accumulator of step 474 accumulates the total number of steps taken by the shoe. This total number of steps is then compared to the manufacturer's recommended number of steps expected in the shoes life time.

FIG. 4D illustrates one process 480 performed by processor 102 of FIG. 1 for determining shoe wear out. In step 481, processor 102 samples detector 104 periodically over a defined period. In one example of step 481, detector 104 is an accelerometer and processor 102 samples acceleration values over a period of 1 second. In step 482, processor 102 determines if the shoe is in use. In one example of step 482, processor 102 utilizes algorithms of software 103 to determine if characteristics of samples values of step 481 indicate that the shoe is in use. Step 483 is a decision. If, in step 483, processor 102 determines that the shoe is in use, process 480 continues with step 484; otherwise process 480 continues with step 486. In step 484, processor 102 determines a distance traveled over the defined period of step 481. In one example of step 484, processor 102 utilizes algorithms of software 103 to first determine speed of the shoe, and then determines distance covered in one second. In step 485, processor 102 accumulates the distance traveled. In one example of step 485, processor 102 adds the distance determined in step 484 to a total distance traveled accumulator. In one example, this accumulator is stored in non-volatile memory. Step 486 is a decision. If, in step 486, processor 102 determines that the shoe is worn out, process 480 continues with step 487; otherwise process 480 continues with step 481. In one example of step 486, processor 102 compares the total accumulated distance of step 485 against the manufacturer's recommended maximum distance for the shoe. Steps 481 through 486 repeat throughout the lifetime of the shoe. As appreciated, power saving measures may be used within sensor 100 when it is determined that the shoe is not in use. In step 487, processor 102 enables alarm 106. In one example of step 487, processor 102 may periodically activate LED 217, FIG. 2, until battery 108 is exhausted. Process 480 thus determines shoe wear by measuring the distance traveled by the shoe, using one or more accelerometers, and compares that distance to a manufacturer's recommended maximum distance for the shoe.

FIG. 5 shows a body bar sensing system 500. System 500 includes a housing 502, a processor 504, a detector 506 and either an internal display 508 or an external display 512. A battery 510 may be used to power processor 504, detector 506 and display 508/512. Detector 506 is for example an accelerometer or a Hall Effect sensor. Display 508/512 is for example a liquid crystal display and/or a small speaker (e.g., that emits voice annunciations or other sounds generated by processor 504).

FIG. 6 shows one part of an exemplary body bar 602 with body bar sensing system 500 attached; a weight 604 and a retaining clip 606 are also shown to secure weight 604 onto body bar 602 (note, some body bars use no weights but weight is shown in FIG. 6 for illustrative purposes). Body bar 602 may represent a work out bar used by people in the gym, or a barbell, or other similar apparatus that requires a number of repetitions in exercise. FIG. 7 shows body bar 602 in an embodiment with another body bar sensing system 500 that secures weight 604 onto body bar 602. That is, sensing system 500 in addition operates as retaining clip 606, FIG. 6.

FIGS. 5, 6 and 7 are best viewed together with the following description. Housing 502 attaches to body bar 602 as shown in FIG. 6 or as shown in FIG. 7. Processor 504 utilizes detector 506 to determine when system 500 (as attached to body bar 602) has performed one repetition; it then informs the user, via display 508/512 for example, of a number of repetitions (or whether the user has performed the right number or any other number of planned repetitions as programmed into processor 504).

Where display 512 is used (i.e., remote from housing 502), a wireless transmitter (not shown) may be included within housing 502 to remotely provide data from processor 504 to remote display 512 (as shown in dotted outline). Where display 508 is integral with housing 502, then display 508 provides a visual display for a user when housing 502 attaches to the body bar. In one embodiment, display 512 (shown in dotted outline) is part of a watch (or a MP3 player or a cell phone) that may be seen when worn or used by the user when performing exercises; and measurements determined by processor 504 are transmitted to the watch (or to the MP3 player or cell phone) for display upon display 512.

Processor 504 may operate under control of algorithmic software 505 (which is illustratively shown within processor 504 although it may reside elsewhere within housing 502, such as stand alone memory within housing 502). Algorithmic software 505 for example includes algorithms for processing data from detector 506 to determine the repetitions performed by a user of body bar 602.

FIG. 8 shown one exemplary process 800 performed by processor 504. In step 802, detector 506 samples a physical metric associated with body bar 602. In an example of step 802, detector 506 is an accelerometer and thereby provides acceleration as the physical metric. In another example of step 802, detector is a Hall effect sensor which detects inversion (and thus repetition) of bar 602. In step 804, processor 504 processes the physical metric to assess whether the metric indicates a repetition of body bar 602. In an example of step 804, processor 504 evaluates the acceleration to determine if body bar 602 has been raised or lowered within a certain time interval. In step 806, repetition information is displayed to the user. In an example of step 806, the number of repetitions is relayed remotely (wirelessly) to a watch that includes display 512. That watch may also include a processor to store data and inform the user of repetitions for workouts, over time.

FIG. 9 shows one exemplary system 900 for unitlessly assessing activity of a user. System 900 has a processor 904, a detector 906 and a battery 908 within an enclosure 902 (e.g., a plastic housing). System 900 may include a display 910 for displaying unitless units to the user. Alternatively (or in addition), a remote display 912 is used to display the unitless units; in this case, enclosure 902 includes a wireless transmitter 913 in communication with, and controlled by, processor 904, so that transmitted unitless assessment numbers are sent to remote display 912.

In an embodiment, detector 906 is an accelerometer and processor 904 determines a value representing an activity level of the user of system 900 for display on display 910 or display 912. The accelerometer is for example positioned within housing 902 so that, when housing 902 is attached to a user, accelerometer 906 senses motion perpendicular to a surface (e.g., ground or a road or a floor) upon which the user moves (e.g., runs, dances, bounces). Data from the accelerometer is for example processed in the frequency domain as power spectral density (e.g., by frequency binning of the data). Multiple accelerometers (e.g., a triaxial accelerometer) may also be used as detector 906—for example to sense motion in other axes in addition to one perpendicular to the surface—and then processed together (e.g., in power spectral density domain) to arrive at a unitless value (as described below).

Processor 904 may utilize one or more algorithms, shown as software 905 within processor 904, for processing information obtained from detector 906 to assess the activity of the user. For example, processor 904 may periodically sample detector 906 to measure acceleration forces experienced by the user (when enclosure 902 is attached to the user, e.g., at the user's belt or shoe). Processor 904 may then process these forces to assess the activity level of the user. This activity level may represent effort exerted by the user when skiing.

The following represents a typical use of system 900, in an embodiment. In this example, detector 906 is one or more accelerometers. First, processor 904 determines when system 900 is in use, for example by sensing movement of housing 902 that corresponds to known activity (e.g., skiing or running). Alternatively, system 900 includes a button 915 that starts processing (in which case, separate determination of a known activity is not necessary). In an embodiment, button 915 is located proximate to display 912, and communicated wirelessly with processor 904. In this case, wireless transmitter 913 is a transceiver and button 915 includes a transmitter or a transceiver.

Once processor 904 knows (by sensing motion) or is notified (by button 915) that system 900 is operating in the desired activity, then it collects data over a period of that activity—for example over 1 hour (a typical aerobic hour), 4 hours (a typical long run), 8 hours (a typical “ski” day) or over one full day, each of these being typical sport activity periods; however any time may be used and/or programmed in system 900. In an example, processor 904 integrates power spectral density of acceleration over this period of time to generate a number. This number in fact is a function of g's, frequency units and time, which does not make intuitive sense to the user. For example, consider a professional athlete who snowboards down difficult, double diamond terrain for eight hours. When system 900 measures his activity over this period, his number will be high (e.g., 500 “units” of power spectral density) because of his extreme physical capabilities. Then, when a less capable user uses system 900, a number of, e.g., 250 units may be generated because the user is not as capable (physically and skilled) as the professional. Therefore, in this example, an expected maximum number, shown as MAX 914 within processor 904, may be set at 500. A display range, shown as RNG 916 within processor 904, may also be defined such that system 900 may display a unitless value that is relative to the maximum number. Continuing with the above example, if RNG 916 is set to 100, system 900 displays a unitless value of 100 for the professional athlete and a unitless value of 50 for the less capable user (i.e., the less capable user has a 50% value of the professional athlete). By setting RNG 916 to other values, the displayed output range of system 900 may be modified.

In one example of use, system 900 is formed as a wrist watch to facilitate attachment to a child's wrist. System 900, when worn by the child, may then determine the child's activity level for the day. In another example of use, system 900 may be attached to a person's limb that is recuperating from injury (e.g., sporting injury, accident and/or operation etc.) such that system 900 may determine if the limb is receiving the right amount of activity to expedite recovery.

In another example of use, two skiers each use a system 900 when skiing for a day. The first skier, who is experienced and athletic, skis difficult ski runs (e.g., black double diamonds) all day, whereas the second skier is less experienced and skis easy runs (e.g., green runs) all day. At the end of the day, the first skier has a unitless activity value of 87 and the second skier has a unitless activity value of 12. Thus, these unitless activity values indicate the relative activity levels of each skier.

FIG. 10 shows a flowchart illustrating one process 1000 for determining and displaying a unitless value representative of a users activity. Process 1000 may represent algorithms within software 905 of FIG. 9, for example, to be executed by processor 904. In step 1002, process 1000 clears a period accumulator. In one example of step 1002, processor 904, under control of software 905, clears period accumulator 918. In step 1004, process 1000 samples the detector to obtain data. In one example of step 1004, processor 904 periodically samples detector 906 over a sample period to determine data representative of the user's activity for that period. In step 1006, process 1000 processes the data of step 1004 to determine a number. In one example of step 1006, processor 904 integrates power spectral density of acceleration sampled in step 1004 over the sample period of step 1004 to generate a number. In step 1008, the number determined in step 1004 is added to the period accumulator. In one example of step 1006, processor 904 adds the number determined in step 1004 to period accumulator 918. In step 1010, process 1000 determines a unitless activity value from the accumulator. In one example of step 1010, processor 904 converts the accumulated value to a display value based upon MAX 914 and RNG 916. In step 1012, process 1000 displays the determined unitless activity value. In one example of step 1012, processor 904 sends the determined unitless activity value to display 912 via wireless transmitter 913. Step 1014 is a decision. If, in step 1014, the activity period for display has ended, process 1000 terminates; otherwise process 1000 continues with step 1004. Steps 1004 through 1014 thus repeat until the desired activity period is over.

Changes may be made to this application without departing from the scope hereof. It should thus be noted that the matter contained in the above description or shown in the accompanying drawings should be interpreted as illustrative and not in a limiting sense. The following claims are intended to cover all generic and specific features described herein, as well as all statements of the scope of the present method and system, which, as a matter of language, might be said to fall there between. 

1. A shoe wear out sensor, comprising: at least one detector for sensing a physical metric that changes as a shoe wears out; a processor configured to: process the physical metric, over time, wherein the physical metric is incremented during use of the shoe; and compare the incremented physical metric to a threshold to determine if the shoe is worn out; and an alarm for informing a user of the shoe when a sole of the shoe is worn out.
 2. The sensor of claim 1, the detector comprising at least one of a force sensing resistor and an accelerometer.
 3. The sensor of claim 2, the processor configured to process acceleration from the detector and then to compare the processed acceleration against similar data of a new shoe.
 4. The sensor of claim 3, the similar data comprising an initialization procedure wherein the shoe sole monitored by the sensor is evaluated prior to initial use by the user.
 5. The sensor of claim 1, the alarm comprising at least one of an LED visible to a user of the shoe and a speaker which emits sound indicating that the shoe sole is worn out.
 6. The sensor of claim 1, further comprising a battery for powering the processor and alarm.
 7. The sensor of claim 1, the detector comprising at least one accelerometer, the physical metric comprising power spectral density of acceleration measured by the accelerometer.
 8. A system for determining the end of a shoe's life, comprising: at least one detector for sensing use of the shoe; a processor configured to: measure the use of the shoe, wherein the measurement is incremented when the shoe is used; and compare the incremented measurement to a threshold to determine if the shoe is worn out; and an alarm for informing a user of the show when the shoe is worn out.
 9. The system of claim 8, wherein the processor measures shoe usage based upon activity detected by the detector.
 10. The system of claim 9, wherein the detector comprises an accelerometer.
 11. The system of claim 8, wherein the detector comprises a piezoelectric foil.
 12. The system of claim 11, wherein the piezoelectric foil generates electricity to power the system when the shoe is in use.
 13. The system of claim 11, wherein the detector comprises a piezoelectric foil to generate electricity to power the system and an accelerometer.
 14. The system of claim 8, the alarm comprising at least one of an LED visible to a user of the shoe and an audible device for emitting a sound to indicate that the shoe is worn out.
 15. The system of claim 8, wherein the use of the shoe is determined based on at least one of detecting weight of the user using the shoe and the duration the shoe is used, assessed weight of the user using the shoe during activity, and the number of steps taken by the shoe.
 16. The system of claim 15, wherein the processor determines the end of the shoe's life based upon the accumulated use of the shoe and the manufacturer expected life. 